Hydrophilic benefit agents (HBAs), especially humectants, but also skin lightening, agents, sunscreens, anti-aging actives etc. can provide benefits to the skin or to hair. At present, however, it is extremely difficult to achieve high levels of deposition and/or to enhance effect of these agents when delivered from personal product compositions, including, but not limited to personal wash liquid cleansers and personal product bars.
While this and co-pending applications are described with personal product language, to the extent the structured benefit agents can be used in a variety of compositions where deposition by benefit agents is desirable (e.g., hair, deodorant), the claims are intended to be read expansively and limited only by structuring component.
Specifically, applicants have found that the use of “structured” benefit agents (the structured benefit agent compositions are separate from the HBA) helps to enhance the effect of the HBA(s). The structured benefit agent may carry or entrap the HBA(s) or the HBA(s) may have been added separate from a premix used to form the structured benefit agent. In the presence of the structured benefit agent, HBA displays enhanced deposition relative to level of deposition of HBA from compositions in which structured benefit agent is not used. According to the invention, preferably the benefit agent being structured and structuring material (e.g., crystalline wax, hydrogenated oil or fat) are separate components.
Specifically, the invention relates to use of benefit agents structured by particular crystalline structurant or structurants (i.e., so that the crystals have specifically defined aspect ratios) wherein, when structured benefit agent is separately prepared before combining with personal product composition, it provides enhanced deposition of HBA (carried on/within the structured benefit agent or added separately) as well as desired skin attributes (e.g. reduction in dryness).
Unlike prior art references where deposition is dependent on the large size of the benefit agent droplets (e.g., >50 micrometers), the deposition results of the subject invention have no requirement of large droplet size and are not dependent on size.
Among the structurants which may be used to structure the carrying benefit agent are natural or synthetic crystalline waxes. Among natural waxes are included petroleum derived waxes such as paraffins and microcrystalline waxes; as well as animal and plant (vegetable) waxes. Among the synthetic crystalline waxes which may be used are crystalline polymers such as polyethylene. Structurants may further include natural or synthetic hydrogenated oils or fats, fatty acids, fatty alcohols, salts of fatty acids, hydroxy fatty acids and fatty acid esters.
When the structured benefit agent(s) carries/entraps HBA(s) (or structured benefit agents are present in final formulation even if HBA(s) is added separate from premix), increased deposition of HBA(s) is achievable. HBA(s) having a wide range of solubility in water can be deposited at increased levels to provide improvements in skin attributes. The HBA of the present invention can be from a wide variety of materials including those from inorganic, organic, natural, and synthetic sources.
Some prior art references purport to use Theological parameters to select oils or oil blends to be used for improving deposition or providing favorable sensory feel.
U.S. Pat. No. 5,674,511 to Kacher et al., for example, describes the use of solubility parameters and four Theological parameters to select benefit agents (i.e., oil or oil blends) that can be used in moisturizing cleansing formulations to improve deposition and provide favorable sensory feels. Petrolatum and petrolatum-containing mixtures are said to be favorable selections. The reference fails to teach or suggest the building of a deformable network of crystals within the benefit agent, and which crystals must have a specific aspect ratio. The Kacher reference fails to teach or suggest that the structured benefit agent be combined with other components in the compositions in a molten, semi-molten or solid state. Also, it does not describe separate benefit agent and structurant, as is preferred by the subject invention (i.e., in the subject invention, if petrolatum is used, it is preferably used as a structurant to structure other benefit agents rather than itself comprise the structured benefit agent). In short, the benefit agents (e.g., oils) of Kacher clearly do not appear to be internally structured delivery vehicles like those used in the compositions of the invention which are separately prepared and wherein structurant has defined aspect ratio.
A number of prior art references disclose generally the concept of an oil additive which can thicken or stabilize oils. They do not, however, teach or disclose that specific crystalline structurant (i.e., having a defined aspect ratio), when prepared in combination with a benefit agent as a premix/delivery vehicle will enhance properties of a separate hydrophilic benefit agent which is carried or entrapped by the structured benefit agent or which HBA is found in the final formulation with the structured benefit agent.
U.S. Pat. No. 5,804,540 to Tsaur et al. and U.S. Pat. No. 5,661,189 to Grieveson, for example, disclose use of both crystalline or micro-crystalline waxes and hydrophobic polymers to thicken low viscosity oil so as to control the oil droplet size (i.e., it must attain a certain minimum size to deposit) as well as to maintain high lather. As noted above, however, there is no discussion of the criticality of crystalline structure (aspect ratio) or that a thickened benefit agent must be separately prepared and added in a molten, semi-molten or solid state. Further, as noted, there is no recognition that it is critical the thickener must be a specific natural or synthetic crystalline structuring material (as defined in the subject invention).
In copending U.S. patent application Ser. No. 09/859,862 to Aronson et al. (entitled “Wet-Skin Treatment Composition”), filed May 17, 2001 and Ser. No. 09/859,849 to Aronson et al. (entitled “Method of Enhanced Moisture or Reduced Drying Using Wet-Skin Treatment Compositions”), there is disclosed benefit agents which provide a draggy feel. There is no teaching or disclosure, however, of using benefit agent structured with crystalline materials of specific aspect ratio (and carrying, containing or in the presence of hydrophilic benefit agents) or of how to produce such.
No prior art of which applicants are aware demonstrates the use of natural or synthetic crystalline structurants (e.g., wax) having specific aspect ratio of crystals and prepared as a premix to enhance the properties of HBA(s) (through deposition of the structured benefit agent carrying the HBA or through other mechanism).